Problem 292

Solution 1

The faces not visible on the top cube are labelled with 2, 3 and 6 dots.

The faces not visible on the bottom cube are labelled with 1, 3, 4, and 5 dots.

Thus, the total number of dots on these other seven faces is $2+3+6+1+3+4+5=24$.

Solution 2

Since each of the two cubes has faces labelled with 1, 2, 3, 4, 5, and 6 dots, then the total number of dots on the two cubes is $2 \times (1+2+3+4+5+6)=2 \times 21=42$.

The five visible faces have a total of $4+1+5+6+2=18$ dots.

Therefore, the seven other faces have a total of $42-18=24$ dots.